Reese Witherspoon had a birthday bash at Warwick, in Hollywood on Saturday night, and from the A-listers in attendance to the fact that Taylor Swift gave a private performance, it sounds like it was quite the party!

The event started around 7:30 p.m., and Reese, who was rocking a sparkly cocktail dress, arrived with hubby Jim Toth shortly thereafter. According to Us Weekly, partygoers included Jennifer Aniston and husband Justin Theroux, Courteney Cox, Matthew McConaughey and wife Camila Alves, Robert Downey Jr. and wife Susan Downey, Nicole Kidman and husband Keith Urban, Tobey Maguire and wife Jennifer Meyer and Kate Hudson. Whew! Reese was showered with gifts, and after Taylor performed, the Oscar winner hopped onstage and sang "Sweet Home Alabama" with Keith Urban.

Kate Hudson posted the photo above and wrote, "When you take a shit load of pictures and you still don't have it perfect so you go for the ole collage post.... Happy Birthday gorgeous girl @reesewitherspoon !!! Love you πŸ‘ΈπŸ’ƒ #TequillaFirst πŸ‘ #PostingLater πŸ˜³πŸ™ˆ #SaturdayNight #ImSoExcitedToGetIntoBedIDontEvenKnowWhatToDoWithMyself #NotWashingMyFace #GoodNight βœ¨πŸ’‹" and she also documented the night's fun on Snapchat.

"It was a great party. When Reese left at 2 a.m., she was in the best mood," a source told Us. "You could tell that she had the best time celebrating her birthday."